What do you see as the downside of tubes?

Krauti:

You cannot run a tube amp 24/7 because the output tubes pass a lot of current and will wear out too quickly. This is generally not the case with gear like tube preamps or tubed DAC's that use small-signal tubes (little tubes) - 24/7 operation with small-signal tubes usually extends life and yields better sound, as turning gear on and off subjects the tubes to harmful thermal cycles, as well as a voltage rush on power up if the gear uses solid-state rectification, which is most gear. The latter factor is the biggest problem, which is another advantage of tube rectification and why a lot of tube preamps have a "soft-start" feature which applies voltage slowly to the tube filaments on power-up.

And as others have noted, a tube amp with a lot of output tubes will heat up a room (extreme cases, like ARC's 600 series reference amps, basically require a separate room or custom air conditioning unless you are running them in a gigantic room).

I have a solid-state amp (darTZeel) and tube amp (VAC Renaissance 70/70) in my living room, and run the solid-state amp most of the time because, like the poster who spawned your question, I like the convenience of being able to listen whenever I want. The VAC sounds good in 10 minutes, but sounds better after a few hours of operation, and I don't like powering up the amp and exposing it to a thermal cycle when I'm only going to listen for a few minutes. I do run the VAC in the spring and summer when there are frequent electrical storms, as I work far from home and am not able to get home to power down the darTZeel during electrical storms.

Just to be clear, the issue with tube amps and 24/7 operation is that the big output tubes pass a lot of current, even while idling, and this creates undue wear. Small signal-tubes, on the other hand, pass very little current in most circuits, and as I have written ad nauseum in other threads on this forum, when left on 24/7, they tend to either die within 200-250 hours from "infant mortality" (defective manufacture), or they basically last forever.

Maineiac, in my first post on this thread, I answered the Krauti's question. In my subsequent posts, I replied to the responses to my posts. "Revelatory, theraputic (just like a good tube amp).)"? Perhaps stepping way from the tubes for a while might offer you some perspective. It's not as though I am insensitive to many of the charms of tubes. I have yet to hear any speakers that do better with tubes that I care to own.

Good point Raquel. While I sometimes keep my preamp and CD player powered up for days at a time, my hybrid amps get powered down at night or whenever I do not expect to be listening for most of the day. I would expect it to be a good idea to power down fully tubed amps for the reasons you state.

As the original poster of this thread I actually like the fact that this thread has taken on it's own life. Think that's just what happens over time as once the downsides I've asked for have been stated thread drift sets in.

That some folks seem to find it necessary to ask what others may be "on" isn't what I had intended, but then again, I have no power over this thread and shouldn't. But hey, this is where that proverbial grain of salt may be helpful.

Raquel, thanks for a clear answer as to why tube amps shouldn't be run 24/7.

Well, it's a long weekend and as there's more to life than audio gear and so I shall try to catch a fish and check back later on the life this thread has taken on. In a way I agree that it has outlived it's usefullness as my questions have been answered and my decision is still the same. Hiho, hiho, and off to tubes I go, hiho hiho, hiho hiho......

Enjoy the long weekend
As far as how many times the same thing needs to repeated I think once or twice is good enough.

Loose bass, forward midrange, bright glassy upper mids/lower highs, rolled off upper highs. Variable performance. Unreliable. High maintance. Difficult to get replacement parts. When they break, they offer the potential to break other links in the system. Excessive heat. Potential burns to children, pets and others. Can cause fires. Requires more care in placement. Limited to use with high impedance speakers. High cost per Watt. Greater sensitivity to speaker cables. Sensitive to vibrations.

Why all the fuss - most of this is quite true although it is a matter of degree. Perhaps Unsound paints an overly negative description for sure, but if you asked people to make a general list of all the cons against tubes they would probably come up with at least four or five items from Unsound's even longer list.

Of course there are a great many pros for tubes starting with their sweet organic, harmonically rich, engaging and musical sound but the OP didn't ask for that.